AB0371 PATIENTS WITH PROLONGED SYMPTOMS BEFORE GCA DIAGNOSIS DO NOT INCUR HIGHER RATES OF VISUAL LOSS

Background:Giant cell arteritis (GCA), if left untreated, confers the threat of serious cranial ischaemic complications including permanent visual loss. Although achieving a prompt and accurate diagnosis remains challenging, early diagnosis is viewed as being paramount in preventing significant morbidity.1 This raises the question of whether GCA patients are at greater risk of developing visual sequelae if there is a longer window between symptom onset and presentation.Objectives:To compare the frequency of lasting visual loss in patients diagnosed with GCA undergoing temporal artery biopsy (TAB) within three months and after three months of symptom onset.Methods:Patients who underwent TAB from January 2011 to November 2020 were identified from the pathology database of an Australian rheumatology referral centre. The diagnosis of GCA was established for each patient based on either positive TAB or, in the setting of negative TAB, clinical diagnosis by a rheumatologist. Baseline demographics, symptoms and major confounders – including age, sex, history of polymyalgia rheumatica or inflammatory arthritis, headache, jaw pain, fatigue, temporal artery tenderness or diminished pulse, and number of 1990 American College of Rheumatology (ACR) classification criteria for GCA2 fulfilled – were manually extracted from electronic medical records, as was the duration between onset of GCA symptoms and TAB, and the presence of visual loss before and after TAB. Logistic regression log-likelihood tests were used to examine the two cohorts presenting before and after three months.Results:There were 167 patients who underwent TAB during the study period with accessible clinical information. Of these, 31 (19%) had a delayed presentation of greater than three months from symptom onset. There were no statistical differences in patient demographics between the two groups (Table 1). No patients with delayed presentation experienced lasting, objective visual loss. In contrast, there were three cases in the cohort of patients who presented more promptly; these included two patients who developed permanent unilateral blindness, and one who experienced unilateral vision loss with some improvement at three months of follow-up.Table 1.Patient characteristics by time from symptom onset to TAB.Presentation Presentation ≥3 monthsp-valueAge (years)73.45±10.0669.84±10.750.080Female92 (67.65%)20 (64.52%)0.738History of polymyalgia rheumatica23 (16.91%)4 (12.90%)0.586History of inflammatory arthritis6 (4.41%)2 (6.45%)0.633Headache110 (80.88%)23 (74.19%)0.406Jaw pain37 (27.21%)5 (16.13%)0.206Fatigue28 (20.59%)6 (19.35%)0.878Temporal artery tenderness or diminished pulse46 (33.82%)11 (35.48%)0.860ACR classification criteria2.83±0.992.58±0.890.199Conclusion:GCA patients with a lengthier course of symptoms before diagnosis did not experience any enduring visual loss. This may reflect a pattern of more aggressive disease leading to earlier presentation, but further study should explore whether longer symptom duration before diagnosis necessitates a higher degree of clinical concern.References:[1]Font C, Cid MC, Coll-Vinent B, López-Soto A, Grau JM. Clinical features in patients with permanent visual loss due to biopsy-proven giant cell arteritis. Br J Rheumatol. 1997 Feb;36(2):251-4. doi: 10.1093/rheumatology/36.2.251. PMID: 9133940.[2]Hunder GG, Bloch DA, Michel BA, Stevens MB, Arend WP, Calabrese LH, Edworthy SM, Fauci AS, Leavitt RY, Lie JT, et al. The American College of Rheumatology 1990 criteria for the classification of giant cell arteritis. Arthritis Rheum. 1990 Aug;33(8):1122-8. doi: 10.1002/art.1780330810. PMID: 2202311.Disclosure of Interests:None declared